基于多规则的船体分段建造空间调度方法

为了解决船体分段在矩形平台建造计划的时空冲突问题,提出了基于时间和空间相似性的分段分类规则。根据分类规则对同一计划期内待调度分段进行归类,形成若干分段类并得到调度计划时间。按照最优可用点搜索法将分段类进行工作平台上的布局安排。对同类分段按照调度计划确定其建造位置和顺序。最后利用软件仿真实际船舶分段建造的空间调度过程,表明该方法是可行且实用的。     

Skid scheduling algorithm for a shipbuilding company

In the small- and medium-sized shipbuilding companies, the skid system, which is a kind of slips located on flat seashore, is widely used. To improve the productivity of the skid, many shipbuilders adopt the semi-tandem system, under which a number of ships can be built on a skid simultaneously. The focus of the research reported in this paper is to develop an efficient spatial schedule for the skid system that uses the semi-tandem system. First, we develop a length-time, two-dimensional packing model for this problem and propose a heuristic algorithm to use the skid efficiently when the launching schedule for ships is given. Then, by combining this heuristic and the GA (genetic algorithm), we develop a hybrid GA algorithm to determine the launching schedule of ships as well as the spatial schedule for the skid, which maximises the number of ships that can be built on the skid and minimises delayed or early launching of each ship. Through performing a series of computational experiments, we finally show that the proposed algorithm can provide solutions of good quality very efficiently.     

面向船体曲面分段建造的虚拟流水线生产调度

基于船舶船体曲面分段建造的特点,利用成组技术和流水线生产的原理,提出了面向曲面分段建造的虚拟流水线生产模式,研究了包括生产组织改造和生产调度的关键技术。根据虚拟流水线生产模式的原理,建立作业班组分解模型,并应用遗传算法实现基于虚拟流水线的曲面分段制造生产调度方法。利用上海某造船厂实际数据进行验证,结果表明虚拟流水线生产模式及方法可有效提高船舶生产效率。     

一种新的聚类分析距离算法

经研究发现现有聚类分析算法普遍存在聚类盲目性,而这又直接影响着聚类的质量.针对这一问题,本文以Parks距离算法为例,提出了一种改良的聚类分析距离算法,并将新距离算法应用在船舶装配产品归类中,经过对改良前后算法的比较,验证了新算法的优越性.     

Automatic generation of a section building planning for constructing complex ships in European shipyards

Efficient planning of the section building process is important for European shipyards since delays in this process can disrupt the on-time delivery of a ship. Automatically generating production schedules of the section building process can result in higher quality schedules compared to those created manually. Recently, the production processes of European shipyards have shifted to focus heavily on outsourcing and outfitting, yet existing automatic planning methods for section building fail to sufficiently consider these factors. This paper develops a mathematical model of the section building process which includes the effects of outfitting and outsourcing. The objective of this model is to simultaneously minimise the fluctuations in workload and the number of outsourced man-hours. The mathematical model was solved by implementing the non-dominated sorting generic algorithm-II (NSGA-II) using a custom heuristic as the fitness function. Due to the multi-objective nature of the problem definition and solution approach, a Pareto front of optimal solutions is created instead of a single, best solution. A test case showed that gains in both objectives are achievable compared to the planning developed manually. Implementing the Section Building Planning methodology developed in this paper could potentially improve the efficiency and controllability of the overall shipbuilding process.     

支持并行工程的造船分段作业计划系统

针对传统造船模式下,车间作业计划与工艺设计串行工作方式的缺点,基于并行工程的原理,提出了分段作业计划与工艺设计的集成运行模式,为实现造船CAPP系统与PPC系统的集成化和并行化提供了实现的基础。针对集成模式的特点,建立了分段作业计划系统资源优化的数学模型,应用遗传算法解决了针对任意分段装配工艺方案的多资源平衡优化问题,可以得到每项作业最优的开工时间,同时能够给出多种资源的最优分布结果,满足了多工艺方案之间资源利用率的比较。最后,给出了计算实例,计算机模拟结果说明了这一方法的有效性。     

基于优先规则的船舶分段空间调度算法

为有效解决船舶分段的空间调度问题,提出了一种基于优先规则的求解算法。首先利用优先规则和禁忌搜索算法产生可行的分段调度序列,再采用一种启发式定位策略——最下最左填满策略对产生的调度序列进行解码,以评估调度序列的优劣。算法不断迭代,最终可得到近似最优解。对船厂的实际生产数据进行了实证分析,并与现有的算法进行了对比,验证了所提出的算法在空间调度问题上的有效性和优越性。     

Integrated process planning and scheduling using an imperialist competitive algorithm

Effective performance of modern manufacturing systems requires integrating process planning and scheduling more tightly, which is consistently challenged by the intrinsic interrelation and intractability of these two problems. Traditionally, these two problems are treated sequentially or separately. Integration of process planning and scheduling (IPPS) provides a valuable approach to improve system performance. However, IPPS is more complex than job shop scheduling or process planning. IPPS is strongly NP-hard in that, compared to an NP-hard job shop scheduling problem with a determined process plan, the process plan for each job in IPPS is also to be optimised. So, an imperialist competitive algorithm (ICA) is proposed to address the IPPS problem with an objective of makespan minimisation. An extended operation-based representation scheme is presented to include information on various flexibilities of process planning with respect to determined job shop scheduling. The main steps of the proposed ICA, including empires construction, assimilation, imperialistic competition, revolution and elimination, are elaborated using an illustrative example. Performance of the proposed ICA was evaluated on four sets of experiments taken from the literature. Computational results of the ICA were compared with that of some existing algorithms developed for IPPS, which validates the efficiency and effectiveness of the ICA in solving the IPPS problem.     

双机无等待流水作业调度算法研究

考虑双机无等待流水作业调度问题,此问题中每台机器都受一个非可用时间的约束,工件都有不同的释放时间.机器的非可用性时间间隔是部分重叠并且已知.目标使Makespan(最大流程时间)最小.通过不同的方式计算上限和下限,完善分支定界法.计算机实验结果显示了所述方法的有效性.     

自主创新,建设造船强国

编者按: 杨槱院士是我国造船学术界的老前辈,长期在学术和管理两个领域耕耘,成就卓著.本文讲的虽然是造船,但文中所谈到的一些基本观点,例如:关于造船(制造业)强国的标志;以人为本,加强工时定额管理;新产品的研究、开发是当务之急等,对我国其他企业也都有借鉴作用.本文是根据杨院士为某报准备的访谈发言稿摘编的,现征得杨院士的同意,特在本刊创刊10周年之际发表,以餐读者.     

标准化助推我国船舶工业由“大”到“强”

本文从建立船舶工业标准体系,应对国际标准新要求,标准化支撑船舶与海洋工程设计与建造、提升配套设备水平、加强船舶行业管理等方面,阐述了标准化发挥的支撑和引领作用,并研究讨论了未来船舶标准化的发展方向,强调大力发展船舶标准化对我国船舶工业实现由"大"到"强",早日成为世界造船强国具有重要意义。     

一类多资源调度问题的优化算法

若调度系统中的作业或任务需要一个或多个资源共同完成, 则这一类调度问题被称为多资源（或多处理机）调度问题。本文针对Jobshop中的这一调度问题,提出了基于遗传的优化调度算法,并用实例证实了该算法的有效性。     

基于遗传算法的平行流水作业计划方法

提出了平行机作业方式和流水作业方式的综合的作业方式,属于NP难问题.应用网络理论构造了平行流水作业的非连接图模型,可实现全局随机寻优的实基因编码遗传算法求解平行流水作业计划问题.选取各种规模的10余个标准算例,以加工流程时间为目标函数进行仿真.对每个算例进行10次随机计算,所得最优值与平均值差异率小于1.8%.对于reC39等大规模问题,10次随机计算的平均花费时间少于260s.